4 default "/lib/modules/$UNAME_RELEASE/.config"
5 default "/etc/kernel-config"
6 default "/boot/config-$UNAME_RELEASE"
7 default "arch/$ARCH/defconfig"
9 menu "Code maturity level options"
12 bool "Prompt for development and/or incomplete code/drivers"
14 Some of the various things that Linux supports (such as network
15 drivers, file systems, network protocols, etc.) can be in a state
16 of development where the functionality, stability, or the level of
17 testing is not yet high enough for general use. This is usually
18 known as the "alpha-test" phase among developers. If a feature is
19 currently in alpha-test, then the developers usually discourage
20 uninformed widespread use of this feature by the general public to
21 avoid "Why doesn't this work?" type mail messages. However, active
22 testing and use of these systems is welcomed. Just be aware that it
23 may not meet the normal level of reliability or it may fail to work
24 in some special cases. Detailed bug reports from people familiar
25 with the kernel internals are usually welcomed by the developers
26 (before submitting bug reports, please read the documents
27 <file:README>, <file:MAINTAINERS>, <file:REPORTING-BUGS>,
28 <file:Documentation/BUG-HUNTING>, and
29 <file:Documentation/oops-tracing.txt> in the kernel source).
31 This option will also make obsoleted drivers available. These are
32 drivers that have been replaced by something else, and/or are
33 scheduled to be removed in a future kernel release.
35 Unless you intend to help test and develop a feature or driver that
36 falls into this category, or you have a situation that requires
37 using these features, you should probably say N here, which will
38 cause the configurator to present you with fewer choices. If
39 you say Y here, you will be offered the choice of using features or
40 drivers that are currently considered to be in the alpha-test phase.
47 depends on BROKEN || !SMP
52 depends on SMP || PREEMPT
55 config INIT_ENV_ARG_LIMIT
60 Maximum of each of the number of arguments and environment
61 variables passed to init from the kernel command line.
68 string "Local version - append to kernel release"
70 Append an extra string to the end of your kernel version.
71 This will show up when you type uname, for example.
72 The string you set here will be appended after the contents of
73 any files with a filename matching localversion* in your
74 object and source tree, in that order. Your total string can
75 be a maximum of 64 characters.
77 config LOCALVERSION_AUTO
78 bool "Automatically append version information to the version string"
81 This will try to automatically determine if the current tree is a
82 release tree by looking for git tags that
83 belong to the current top of tree revision.
85 A string of the format -gxxxxxxxx will be added to the localversion
86 if a git based tree is found. The string generated by this will be
87 appended after any matching localversion* files, and after the value
88 set in CONFIG_LOCALVERSION
90 Note: This requires Perl, and a git repository, but not necessarily
91 the git or cogito tools to be installed.
94 bool "Support for paging of anonymous memory (swap)"
98 This option allows you to choose whether you want to have support
99 for so called swap devices or swap files in your kernel that are
100 used to provide more virtual memory than the actual RAM present
101 in your computer. If unsure say Y.
106 Inter Process Communication is a suite of library functions and
107 system calls which let processes (running programs) synchronize and
108 exchange information. It is generally considered to be a good thing,
109 and some programs won't run unless you say Y here. In particular, if
110 you want to run the DOS emulator dosemu under Linux (read the
111 DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
112 you'll need to say Y here.
114 You can find documentation about IPC with "info ipc" and also in
115 section 6.4 of the Linux Programmer's Guide, available from
116 <http://www.tldp.org/guides.html>.
119 bool "POSIX Message Queues"
120 depends on NET && EXPERIMENTAL
122 POSIX variant of message queues is a part of IPC. In POSIX message
123 queues every message has a priority which decides about succession
124 of receiving it by a process. If you want to compile and run
125 programs written e.g. for Solaris with use of its POSIX message
126 queues (functions mq_*) say Y here. To use this feature you will
127 also need mqueue library, available from
128 <http://www.mat.uni.torun.pl/~wrona/posix_ipc/>
130 POSIX message queues are visible as a filesystem called 'mqueue'
131 and can be mounted somewhere if you want to do filesystem
132 operations on message queues.
136 config BSD_PROCESS_ACCT
137 bool "BSD Process Accounting"
139 If you say Y here, a user level program will be able to instruct the
140 kernel (via a special system call) to write process accounting
141 information to a file: whenever a process exits, information about
142 that process will be appended to the file by the kernel. The
143 information includes things such as creation time, owning user,
144 command name, memory usage, controlling terminal etc. (the complete
145 list is in the struct acct in <file:include/linux/acct.h>). It is
146 up to the user level program to do useful things with this
147 information. This is generally a good idea, so say Y.
149 config BSD_PROCESS_ACCT_V3
150 bool "BSD Process Accounting version 3 file format"
151 depends on BSD_PROCESS_ACCT
154 If you say Y here, the process accounting information is written
155 in a new file format that also logs the process IDs of each
156 process and it's parent. Note that this file format is incompatible
157 with previous v0/v1/v2 file formats, so you will need updated tools
158 for processing it. A preliminary version of these tools is available
159 at <http://www.physik3.uni-rostock.de/tim/kernel/utils/acct/>.
162 bool "Export task/process statistics through netlink (EXPERIMENTAL)"
166 Export selected statistics for tasks/processes through the
167 generic netlink interface. Unlike BSD process accounting, the
168 statistics are available during the lifetime of tasks/processes as
169 responses to commands. Like BSD accounting, they are sent to user
174 config TASK_DELAY_ACCT
175 bool "Enable per-task delay accounting (EXPERIMENTAL)"
177 Collect information on time spent by a task waiting for system
178 resources like cpu, synchronous block I/O completion and swapping
179 in pages. Such statistics can help in setting a task's priorities
180 relative to other tasks for cpu, io, rss limits etc.
185 bool "Sysctl support" if EMBEDDED
188 The sysctl interface provides a means of dynamically changing
189 certain kernel parameters and variables on the fly without requiring
190 a recompile of the kernel or reboot of the system. The primary
191 interface consists of a system call, but if you say Y to "/proc
192 file system support", a tree of modifiable sysctl entries will be
193 generated beneath the /proc/sys directory. They are explained in the
194 files in <file:Documentation/sysctl/>. Note that enabling this
195 option will enlarge the kernel by at least 8 KB.
197 As it is generally a good thing, you should say Y here unless
198 building a kernel for install/rescue disks or your system is very
202 bool "Auditing support"
205 Enable auditing infrastructure that can be used with another
206 kernel subsystem, such as SELinux (which requires this for
207 logging of avc messages output). Does not do system-call
208 auditing without CONFIG_AUDITSYSCALL.
211 bool "Enable system-call auditing support"
212 depends on AUDIT && (X86 || PPC || PPC64 || S390 || IA64 || UML || SPARC64)
213 default y if SECURITY_SELINUX
215 Enable low-overhead system-call auditing infrastructure that
216 can be used independently or with another kernel subsystem,
217 such as SELinux. To use audit's filesystem watch feature, please
218 ensure that INOTIFY is configured.
221 bool "Kernel .config support"
223 This option enables the complete Linux kernel ".config" file
224 contents to be saved in the kernel. It provides documentation
225 of which kernel options are used in a running kernel or in an
226 on-disk kernel. This information can be extracted from the kernel
227 image file with the script scripts/extract-ikconfig and used as
228 input to rebuild the current kernel or to build another kernel.
229 It can also be extracted from a running kernel by reading
230 /proc/config.gz if enabled (below).
233 bool "Enable access to .config through /proc/config.gz"
234 depends on IKCONFIG && PROC_FS
236 This option enables access to the kernel configuration file
237 through /proc/config.gz.
240 bool "Cpuset support"
243 This option will let you create and manage CPUSETs which
244 allow dynamically partitioning a system into sets of CPUs and
245 Memory Nodes and assigning tasks to run only within those sets.
246 This is primarily useful on large SMP or NUMA systems.
251 bool "Kernel->user space relay support (formerly relayfs)"
253 This option enables support for relay interface support in
254 certain file systems (such as debugfs).
255 It is designed to provide an efficient mechanism for tools and
256 facilities to relay large amounts of data from kernel space to
264 bool "Enable 16-bit UID system calls" if EMBEDDED
265 depends on ARM || CRIS || FRV || H8300 || X86_32 || M68K || (S390 && !64BIT) || SUPERH || SPARC32 || (SPARC64 && SPARC32_COMPAT) || UML || (X86_64 && IA32_EMULATION)
268 This enables the legacy 16-bit UID syscall wrappers.
270 config CC_OPTIMIZE_FOR_SIZE
271 bool "Optimize for size (Look out for broken compilers!)"
273 depends on ARM || H8300 || EXPERIMENTAL
275 Enabling this option will pass "-Os" instead of "-O2" to gcc
276 resulting in a smaller kernel.
278 WARNING: some versions of gcc may generate incorrect code with this
279 option. If problems are observed, a gcc upgrade may be needed.
284 bool "Configure standard kernel features (for small systems)"
286 This option allows certain base kernel options and settings
287 to be disabled or tweaked. This is for specialized
288 environments which can tolerate a "non-standard" kernel.
289 Only use this if you really know what you are doing.
292 bool "Load all symbols for debugging/kksymoops" if EMBEDDED
295 Say Y here to let the kernel print out symbolic crash information and
296 symbolic stack backtraces. This increases the size of the kernel
297 somewhat, as all symbols have to be loaded into the kernel image.
300 bool "Include all symbols in kallsyms"
301 depends on DEBUG_KERNEL && KALLSYMS
303 Normally kallsyms only contains the symbols of functions, for nicer
304 OOPS messages. Some debuggers can use kallsyms for other
305 symbols too: say Y here to include all symbols, if you need them
306 and you don't care about adding 300k to the size of your kernel.
310 config KALLSYMS_EXTRA_PASS
311 bool "Do an extra kallsyms pass"
314 If kallsyms is not working correctly, the build will fail with
315 inconsistent kallsyms data. If that occurs, log a bug report and
316 turn on KALLSYMS_EXTRA_PASS which should result in a stable build.
317 Always say N here unless you find a bug in kallsyms, which must be
318 reported. KALLSYMS_EXTRA_PASS is only a temporary workaround while
319 you wait for kallsyms to be fixed.
323 bool "Support for hot-pluggable devices" if EMBEDDED
326 This option is provided for the case where no hotplug or uevent
327 capabilities is wanted by the kernel. You should only consider
328 disabling this option for embedded systems that do not use modules, a
329 dynamic /dev tree, or dynamic device discovery. Just say Y.
333 bool "Enable support for printk" if EMBEDDED
335 This option enables normal printk support. Removing it
336 eliminates most of the message strings from the kernel image
337 and makes the kernel more or less silent. As this makes it
338 very difficult to diagnose system problems, saying N here is
339 strongly discouraged.
342 bool "BUG() support" if EMBEDDED
345 Disabling this option eliminates support for BUG and WARN, reducing
346 the size of your kernel image and potentially quietly ignoring
347 numerous fatal conditions. You should only consider disabling this
348 option for embedded systems with no facilities for reporting errors.
353 bool "Enable ELF core dumps" if EMBEDDED
355 Enable support for generating core dumps. Disabling saves about 4k.
359 bool "Enable full-sized data structures for core" if EMBEDDED
361 Disabling this option reduces the size of miscellaneous core
362 kernel data structures. This saves memory on small machines,
363 but may reduce performance.
370 bool "Enable futex support" if EMBEDDED
374 Disabling this option will cause the kernel to be built without
375 support for "fast userspace mutexes". The resulting kernel may not
376 run glibc-based applications correctly.
379 bool "Enable eventpoll support" if EMBEDDED
382 Disabling this option will cause the kernel to be built without
383 support for epoll family of system calls.
386 bool "Use full shmem filesystem" if EMBEDDED
390 The shmem is an internal filesystem used to manage shared memory.
391 It is backed by swap and manages resource limits. It is also exported
392 to userspace as tmpfs if TMPFS is enabled. Disabling this
393 option replaces shmem and tmpfs with the much simpler ramfs code,
394 which may be appropriate on small systems without swap.
398 bool "Use full SLAB allocator" if EMBEDDED
400 Disabling this replaces the advanced SLAB allocator and
401 kmalloc support with the drastically simpler SLOB allocator.
402 SLOB is more space efficient but does not scale well and is
403 more susceptible to fragmentation.
405 config VM_EVENT_COUNTERS
407 bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
409 VM event counters are only needed to for event counts to be
410 shown. They have no function for the kernel itself. This
411 option allows the disabling of the VM event counters.
412 /proc/vmstat will only show page counts.
414 endmenu # General setup
422 default 0 if BASE_FULL
423 default 1 if !BASE_FULL
429 menu "Loadable module support"
432 bool "Enable loadable module support"
434 Kernel modules are small pieces of compiled code which can
435 be inserted in the running kernel, rather than being
436 permanently built into the kernel. You use the "modprobe"
437 tool to add (and sometimes remove) them. If you say Y here,
438 many parts of the kernel can be built as modules (by
439 answering M instead of Y where indicated): this is most
440 useful for infrequently used options which are not required
441 for booting. For more information, see the man pages for
442 modprobe, lsmod, modinfo, insmod and rmmod.
444 If you say Y here, you will need to run "make
445 modules_install" to put the modules under /lib/modules/
446 where modprobe can find them (you may need to be root to do
452 bool "Module unloading"
455 Without this option you will not be able to unload any
456 modules (note that some modules may not be unloadable
457 anyway), which makes your kernel slightly smaller and
458 simpler. If unsure, say Y.
460 config MODULE_FORCE_UNLOAD
461 bool "Forced module unloading"
462 depends on MODULE_UNLOAD && EXPERIMENTAL
464 This option allows you to force a module to unload, even if the
465 kernel believes it is unsafe: the kernel will remove the module
466 without waiting for anyone to stop using it (using the -f option to
467 rmmod). This is mainly for kernel developers and desperate users.
471 bool "Module versioning support"
474 Usually, you have to use modules compiled with your kernel.
475 Saying Y here makes it sometimes possible to use modules
476 compiled for different kernels, by adding enough information
477 to the modules to (hopefully) spot any changes which would
478 make them incompatible with the kernel you are running. If
481 config MODULE_SRCVERSION_ALL
482 bool "Source checksum for all modules"
485 Modules which contain a MODULE_VERSION get an extra "srcversion"
486 field inserted into their modinfo section, which contains a
487 sum of the source files which made it. This helps maintainers
488 see exactly which source was used to build a module (since
489 others sometimes change the module source without updating
490 the version). With this option, such a "srcversion" field
491 will be created for all modules. If unsure, say N.
494 bool "Automatic kernel module loading"
497 Normally when you have selected some parts of the kernel to
498 be created as kernel modules, you must load them (using the
499 "modprobe" command) before you can use them. If you say Y
500 here, some parts of the kernel will be able to load modules
501 automatically: when a part of the kernel needs a module, it
502 runs modprobe with the appropriate arguments, thereby
503 loading the module if it is available. If unsure, say Y.
508 depends on (SMP && MODULE_UNLOAD) || HOTPLUG_CPU
510 Need stop_machine() primitive.
514 source "block/Kconfig"